Patent Literature 1 cited below discloses a radar video creation apparatus for creating images for video from raw data which is unprocessed data and observed by a radar apparatus in spotlight mode.
Patent Literature 1 describes as a conventional art a method in which, when raw data which is collected by a radar apparatus observing in spotlight mode is obtained, the raw data is divided into a plurality of pieces of partial raw data, and an image production process is performed on each piece of partial raw data, by which a plurality of partial SAR images are created, enabling to check changes in an observed area.
On the other hand, according to the invention described in Patent Literature 1, a process of extracting a plurality of pieces of partial raw data is performed by cutting out raw data with overlapping between pieces of partial raw data allowed, instead of by dividing raw data. SAR images obtained by performing such cutting-out of raw data and an image production process smoothly change, and thus, more detailed changes in a target can be checked.